| 摘要 |
<p>991,950. Valves. EDWARD VALVES Inc. July 1, 1963 [Aug. 2, 1962], No. 26035/63. Heading F2V. [Also in Division H2] An actuator for a valve 40, Fig. 2A, includes a reversible electric motor 38, Fig. 2B, having means repeatedly reversing its direction of rotation to operate an impact mechanism connected to the valve. The valve 40 is rotatably attached to a stem 52, Fig. 2A, which is threaded into a sleeve 104, in turn screwed into a backing member 55 held in the casing 32 whereby rotation of the stem is transformed into axial displacement. The valve position is shown by a magnetically attractable element 396, Fig. 2B, slidable in a scale 388 and coacting with a magnet 368 on an extension 370 of the motor shaft. Impact mechanism.-The stem 52 extends beyond the member 55 where it rotatably supports a hammer 140 and a plate 148 keyed to the motor shaft 54, the hammer 140 cooperating with an anvil 144 fixed to the stem and having lugs 198, 199 that are arranged to be struck by hammer lugs 201, 202. Electric motor.-The stator laminations 234 are held between flanges 239, 240 of an adjustable shell 238 which latter embodies cooling passages 250. Rotor laminations 288, which are secured to an axially-movable rotor-shaft 54, carry cast rotor bars 296; the rotor laminations are larger than the stator laminations by an amount at least equal to the length of valve travel. Energization of the motor is controlled by a programmed timing mechanism not shown. The windings may be coated with polyvinyl chloride or polyethylene and the motor is immersed in coolant, e.g. the fluid controlled by the valve and led to the motor via a tube 404, Fig. 2A, which tube also acts to equalize the pressure differential generated when the valve moves from the open to the closed position. Alternatively, a pressure equalizing passage may be provided directly through the member 55. In a modification, the entire electric motor moves axially to operate the impact mechanism, the stator shell being mounted on bearings in the casing; the supply leads which are coiled to accommodate movement of the motor, are contained in a telescopic housing. The motor part of the valve casing may be enclosed in a cooling jacket. In another modification, the motor part of the casing 730, Fig. 5, surrounds a sealed container 734 for the stator; a coolant in the container circulates about the stator windings 758 from a tube 762 extending to a pressure equalization chamber 770 and terminating in a bellows 774; the chamber 770 opens into the casing 730. The rotor is axially displaceable relative to the stator.</p> |
